Problem: Which of the following numbers is a factor of 110? ${8,11,12,13,14}$
Solution: By definition, a factor of a number will divide evenly into that number. We can start by dividing $110$ by each of our answer choices. $110 \div 8 = 13\text{ R }6$ $110 \div 11 = 10$ $110 \div 12 = 9\text{ R }2$ $110 \div 13 = 8\text{ R }6$ $110 \div 14 = 7\text{ R }12$ The only answer choice that divides into $110$ with no remainder is $11$ $ 10$ $11$ $110$ We can check our answer by looking at the prime factorization of both numbers. Notice that the prime factors of $11$ are contained within the prime factors of $110$ $110 = 2\times5\times11 11 = 11$ Therefore the only factor of $110$ out of our choices is $11$. We can say that $110$ is divisible by $11$.